The present invention relates to a two-dimensional radiation detecting apparatus for two-dimensionally detecting radiation such as X-rays.
FIG. 1 illustrates an example of a conventional two-dimensional radiation detecting apparatus which is applied for detecting X-rays. In the figure, reference numeral 1 designates an X-ray tube, 2 an object under diagnosis, 3 a scintillator, 4 a light detector. The scintillator 3 and the light detector 4 cooperate to form a two-dimensional X-ray detecting apparatus. The scintillator is made of material such as NaI(Tl), CaF.sub.2, CsI(Tl), CsF, BaF.sub.2, Bi.sub.4 Ge.sub.3 O.sub.12, CaWO.sub.4, and CdWO.sub.4. X-rays radiated from the X-ray tube 1 are applied to the scintillator 3 through the object 2. When the scintillator 3 is irradiated with X-rays, it interacts with the X-rays and emits fluorescence or phosphorescence. The color of the light emitted is determined by material of the scintillator 3. An electrical signal representing the detected light is applied to a data processor 5 where it is converted into a video signal. The video signal is then input to a display 6 which then displays an image representing the object on the screen.
In the two-dimensional radiation detecting apparatus as shown in FIG. 1, the size of the two-dimensional light detector 4 must be equal to that of the scintillator 3 covering a radiographing area. This results in an increase in manufacturing cost of the apparatus. Further, the spatial resolution of the image obtained depends on the performance of the light detector 4.